This invention is concerned with novel polypeptides particularly polypeptides containing at least four and up to about eight amino acids as well as their pharmacologically acceptable derivatives and salts. These compounds are useful both orally and parenterally as mammalian contraceptives.
The principal class of compounds now utilized as contraceptives for animals, including humans, are steroidal in nature. The most widely employed agents are combinations of progestogens such as norethindrone and ethynodiol with estrogens such as ethynyl estradiol and mestranol. The use of such oral contraceptives is associated with a certain degree of well recognized risk. The principal risk is the occurrence of thromboembolism, although other side effects such as increased blood pressure and alterations in metabolism of both lipids and carbohydrates have been recognized, as well as a variety of other symptoms such as headache, fluid and salt retention, bloating, and nausea.
Accordingly, the art has long been interested in finding suitable substitutes for steroidal contraceptives.